Previously, conveyors for transporting a vehicle or other object in one direction along a track have employed power-driven endless chains mounting at least one and usually a plurality of spaced pusher dollies connected thereto. Various efforts have been made to support the endless chain during its longitudinal movements. Chain support rollers have been shown in Applicant's Assignee U.S. Pat. Nos. 4,576,098 and 4,690,065, namely the rollers 131, FIG. 7, and in U.S. Pat. No. 4,715,287, the rollers 55, FIG. 5.
While the foregoing rollers provide a moving support for the respective power-operated endless chains disclosed in said patents, nevertheless there has existed the problem of accidental transverse deflection of the driven chain from the longitudinal centerline of the conveyor to such extent that the supports for the corresponding dollies may become disengaged or fall through the slot in the adjacent track, rendering the conveyor mechanism inoperative.
The present invention represents an improvement in the disclosure of Applicant's Assignee U.S. Pat. No. 4,715,287 of Dec. 29, 1987 wherein there is disclosed a similar conveyor mechanism for transporting a vehicle but wherein no guide means are provided restraining the conveyor sprocket chain against lateral translation such as might permit the corresponding dolly rollers 38 in said patent from dropping through the central slot within the intermediate track 51. Such slot is enlarged as a result of wear of the longitudinal edges thereof caused by the links of the dollies rubbing against the middle track, enlarging the slot, and permitting the rollers of the dolly to drop or fall off the track.